Lecture 26- Digestive Physiology And Kidneys

Question 1

Where doe most digestion occur?

Answer 1

In the small intestine

Question 2

Lacteals

Answer 2

Lymphatic vessels for carrying lipids absorbed in these intestine

Question 3

Carbohydrate digestion

Answer 3

Begins in the mouth as salivary amylase splits starch into oligosaccharides

In intestine, pancreatic amylase breaks down starch and glycogen into oligosaccharides and disaccharides

Brush border enzymes break oligosaccharides and disaccharides into monosaccharides

Monosaccharides are co transported across apical membrane of absorptive epithelial cells and exit across basolateral membrane by facilitated diffusion

Question 4

Lactose intolerance

Answer 4

Person has a deficient amount of lactase

Question 5

Proteins in digestion

Answer 5

Pepsin, secreted by chief cells begins hydrolysis of denatured proteins in stomach

Pancreatic proteases breaks down proteins and proteins fragments into smaller pieces and some individual amino acids in small intestine

Brush border enzymes break oligopeptides and dipeptides into amino acids

Amino acids co transported across apical membrane of absorptive epithelial cell and exit across basolateral membrane by facilitated diffusion

Question 6

lipid digestion

Answer 6

Small intestine is first site of lipid digestion

Bile salts emulsify lipids from large droplets into smaller droplets

Pancreatic lipases break down emulsified fats into monoglycerides and free fatty acids

Monoglcerides and fatty acids combine with bile salts and lecithin to form micelles

At plasma membrane fatty acids and monoglycerides diffuse into epithelial cells of mucosa

Monoglycerides and fatty acids converted back to triglycerides and combined with lecithin, cholesterol and other lions to form chylomicrons, Exocytosed to interstitial space and taken into lacteals for transport

Question 7

How are nuclei acids hydrolysed?

Answer 7

By pancreatic nucleuses in pancreatic juice

Question 8

Vitamins

Answer 8

Organize cofactors that help with metabolism

Most absorbed through small intestine

Question 9

Water soluble vitamins

Answer 9

Bs and C

Absorbed by diffusion or by passive or active transport

Question 10

Fat soluble vitamins

Answer 10

A, D,E,K
Carried by micelles of lipids and diffuse into absorptive cells

Question 11

What percentage of water in chyme does small intestine absorb?

Answer 11

90%

Question 12

How do kidneys maintain body’s internal environment?

Answer 12

Regulating total blood volume and total solute concentration in blood

Regulating ion concentrations

Ensuring long term pH balance

Excreting metabolic wastes, toxins and drugs

Producing erythropoietin and renin and activating vitamin D

Question 13

Three layers of suppportive tissue around kidney

Answer 13

Renal fascia- dense fibrous connective tissue, anchors kidney and adrenal gland to surrounding structures

Perirenal fat capsule- surrounds and cushions kidney

Fibrous capsule- prevents surrounding infections from reaching kidney

Question 14

Blood supply to kidney

Answer 14

Blood enters through on renal artery, flows to cortex until it arrives at afferent arterioles (give rise to microscopic vasculature, key element of kidney function)

Question 15

Renal nerve plexus

Answer 15

Regulates renal blood flow by adjusting diameter of renal arteriole and influencing urine forming role of nephrons

Question 16

Filtrate

Answer 16

Contains almost everything found in plasma except proteins and is refined to urine

Question 17

Nephrons

Answer 17

Structural and functiona units that form urine